1. Field of the Invention
The present invention relates to a heat sink in which thin-sheet fins are crimped firmly, a method for manufacturing the heat sink, and a pressing jig used to manufacture the heat sink.
2. Description of Related Art
Conventionally, a heat sink is manufactured by a method described below as shown in FIG. 15(a). In this method, thin-sheet fins 30 are inserted in a plurality of grooves 20 formed in parallel in the surface of a base plate 61 to which the thin-sheet fins 30 are attached. A pressing end portion 50 of a pressing jig 60 is pressed against a portion 40 in the vicinity of both sides of each of the grooves 20. The pressing end portion 50 of the pressing jig 60 has a triangular cross section, i.e., a blade with sharp edge.
An embodiment of a heat sink of the present invention is a heat sink comprising a base plate provided with a plurality of grooves and concave portions, each of which concave portions has a substantially trapezoidal cross section having a flat bottom face and inclined side faces and is formed into a tapered shape, formed between the adjacent grooves by plastic deformation; and
a plurality of thin-sheet fins which are inserted in the grooves and are crimped from both sides by the inclined side faces formed by the plastic deformation of the concave portions.
An embodiment of a method for manufacturing a heat sink of the present invention is a method for manufacturing a heat sink, comprising the steps of:
forming a plurality of grooves in the surface of a base plate to which thin-sheet fins are attached;
inserting the thin-sheet fins in the grooves; and
forming concave portions, each of which has a substantially trapezoidal cross section having a flat bottom face and inclined side faces and is formed into a tapered shape, by plastic deformation in a portion in the vicinity of both sides of the groove in the surface to which the thin-sheet fins are attached, so that the thin-sheet fins are crimped in the grooves.
An embodiment of a pressing jig of the present invention is a pressing jig used in the manufacturing method for a heat sink, in which a pressing end portion of the pressing jig has a substantially trapezoidal cross section and is formed into a tapered shape.